As a public official, a notary public has the authority to create authentic deeds with full evidentiary force. In practice, a notary's responsibility is often understood to be limited to formalities, namely ensuring that formal requirements as stipulated in laws and regulations are met. However, it is not uncommon to find authentic deeds that are formally valid but contain substantial problems, resulting in disputes and losses for the parties. This issue raises questions about whether limiting notaries' responsibilities to formalities is sufficient to guarantee the validity of authentic deeds and how notaries' liability for the substantial truth of authentic deeds should be constructed to ensure legal certainty and justice. This study aims to analyze the limits of notaries' liability regarding formalities and examine the possibility of accountability for the substance of authentic deeds. The research method used is normative legal research, utilizing a legislative approach, a conceptual approach, and a case study approach. The legal sources used include primary legal materials in the form of the Civil Code, the UUJNP, secondary legal materials in the form of literature and journals, and tertiary legal materials in the form of legal dictionaries. The legal materials were analyzed qualitatively. The results of this study indicate that notary liability are essentially limited to formal aspects, but under certain circumstances can extend to substantial aspects if there is an element of negligence or a violation of the principle of prudence. Therefore, a reconstruction of notary liability is needed that emphasizes not only formalities but also integrates the principle of prudence to achieve a balance between legal certainty and justice.